Schools in England are very old; schools have been founded since the Roman occupation of Britain, after the disappearance of Roman schools. A new school was founded in 597 by Saint Augustine. The Viking invasions were a bad factor against schools in England. Schools have resumed activity despite continued invasions (Gillard, 2011). Schools expanded and developed between 1100 and 1500, with the English Renaissance contributing positively to this. The Elizabethan I period (1558-1603) witnessed a revolution in education and the school system. From 1800, educational theories developed and schools took on a modern form. The schools were predominantly single-sex (male schools) until the 19th century; female students begin to attend these schools. The modern school system can be classified into two main categories: co-educational schools and single-sex schools, the latter of which can be described as single-sex education; it is the implementation of education with students of the same sex, men or women separately, in several societies, this separation due to religion or tradition is at the origin. Single-sex schools dominated until the 19th century, when coeducation began and grew. Mixedness (mixed sex education), it could be described as mixed education between the sexes; it is education where male and female students study together in the same classes, buildings or schools. At the end of the 20th century, coeducation became the dominant school system. The coeducational education system is the dominant system in most British schools (Department for Education and Skills, 2007). The essay attempts to assess the problems of co-ed schools, compared to single-sex schools. The main argument in favor of the application of single-sex schools is considered in the first place...... in the middle of the article ......ide Web. Accessed May 8, 2014, from http://dx.doi.org/10.1080/03057640902903722Single sex education (2013) Available on the World Wide Web. Accessed 26 May 2014 from www.ukboardingschools.com/advice/single-sex-education/Skelton, C. (2010) 'Gender and achievement: are girls the 'success stories' of restructured education systems', Routledge, Educational review [online], vol. 62 no. 2 Available on the World Wide Web. Accessed May 8, 2014, from http://dx.doi.org/10.1080/00131910903469536 Tobias, L. (2013) “Single-sex or mixed schools? ". Available on the World Wide Web. Accessed 26 May 2014 from http://www.gettherightschool.co.uk/single-sex-mixed-schools.htmlYounger, M. et al (2005) Raising Boys Achievement, Faculty of Education, University of Cambridge. Available on the World Wide Web. Accessed May 10, 2014 from https://www.education.gov.uk/publications/.../RR636.pdf